Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Defined Benefit Plan Disclosure [Line Items] | ||||
| Net periodic benefit cost | $ (31) | $ (253) | $ (62) | $ (508) |
| United States [Member] | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Interest cost | 1,646 | 1,700 | 3,292 | 3,400 |
| Expected return on plan assets | (1,847) | (2,003) | (3,695) | (4,005) |
| Amortization of net actuarial loss (gain) | 109 | (19) | 217 | (38) |
| Net periodic benefit cost | (92) | (322) | (186) | (643) |
| United Kingdom [Member] | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Interest cost | 178 | 178 | 357 | 346 |
| Expected return on plan assets | (201) | (206) | (403) | (400) |
| Amortization of net actuarial loss (gain) | 85 | 97 | 170 | 189 |
| Net periodic benefit cost | $ 62 | $ 69 | $ 124 | $ 135 |
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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